bicycle front derailleur

Abstract

Bicycle front derailleur (10) comprising: a fixing element (12) which is designed to be fixed to a bicycle frame; a chain guide (14) movable between a retracted position and an extended position with respect to the fixing element (12); a connecting mechanism (16) that couples the chain guide (14) to the fixing link (12), wherein the connecting mechanism (16) includes a first connecting link (18) which is pivotable with respect to the fixing link (12) about a first axis (A1) and which is pivotable with respect to the chain guide (14) about a second axis (A2) which is positioned above the first axis (A1) when the fixing link (12) is fixed to the bicycle frame, and wherein the connecting mechanism (16) includes a second connecting link (20) which is pivotable with respect to the fixing link (12) about a third axis (A3) and which is pivotable with respect to the chain guide (14) about a fourth axis (A4) which is positioned above the third axis (A3) when the fixing link (12) is fixed to the bicycle frame, wherein the first connecting link (18) and the second connecting link (20) form a four-bar linkage,and wherein the second axis (A2) is positioned between the fourth axis (A4) and the chain guide (14); and , a biasing member (24) which biases the chain guide (14) in the direction of the retracted position or the extended position, wherein the biasing member (24) is arranged coaxially about the second axis (A2), wherein the chain guide (14) includes two pivot openings (36e, 36f) which at least partially define the second axis (A2).

Description

[0001] This application claims priority to US patent application No. 13 / 898,733 (US 2014 / 0 349 794 A1), filed on May 21, 2013. The entire disclosure of US patent application No. 13 / 898,733 (US 2014 / 0 349 794 A1) is hereby incorporated by reference. Field of the invention

[0002] The present invention relates to a bicycle front derailleur. Background of the invention

[0003] Bicycle front derailleurs are well known and typically include a chain guide that moves the chain from one chainring (sprocket) to another chainring in response to the cyclist's input. For example, see US Patent No. 7,438,657 B2 to Nakai, which is incorporated herein by reference in its entirety. Other bicycle front derailleurs with a linking mechanism are known from DE 34 11 874 A1, US 2007 / 0 298 920 A1, US 2008 / 0 305 902 A1, US 4 226 130 A, and DE 29 49 377 A1. There is a need for an improved bicycle front derailleur. The technical problem of the present application is to provide a bicycle front derailleur comprising a chain guide, wherein the derailleur provides a durable and robust connection of the chain guide capable of absorbing external shocks, forces and loads when using the bicycle. Summary of the preferred embodiments

[0004] The above-mentioned object is achieved according to a first aspect of the present invention by a bicycle front derailleur, which includes a fixing member configured to be fixed to a bicycle frame, a chain guide movable between a retracted position and an extended position with respect to the fixing member, a linking mechanism coupling the chain guide to the fixing member, and a biasing member biasing the chain guide toward the retracted position or the extended position. The linking mechanism includes a first link pivotable with respect to the fixing member about a first axis and pivotable with respect to the chain guide about a second axis positioned above the first axis when the fixing member is fixed to the bicycle frame.The link mechanism includes a second link pivotable with respect to the fixing link about a third axis and pivotable with respect to the chain guide about a fourth axis positioned above the third axis when the fixing link is fixed to the bicycle frame, wherein the first link and the second link together form a four-bar linkage, and wherein the second axis is positioned between the fourth axis and the chain guide. The biasing link is arranged coaxially about the second axis. The chain guide includes two pivot openings that at least partially define the second axis. In a preferred embodiment, the first link includes a first arm and a second arm, each of which extends between the first and second axes, and wherein the biasing link is arranged between the first arm and the second arm.

[0005] In a preferred embodiment, the first axis and the third axis lie in a first plane, and the second axis and the fourth axis lie in a second plane. Preferably, the first plane is approximately perpendicular to a central axis of the bicycle frame when the fixing member is fixed to the bicycle frame. Furthermore, the second plane is approximately perpendicular to the central axis of the bicycle frame when the fixing member is fixed to the bicycle frame. In a preferred embodiment, the second connecting member has a cable fixing portion. Preferably, the cable fixing portion is positioned between the second axis and the fourth axis in a substantially horizontal direction. In a preferred embodiment, the biasing member is arranged coaxially around the second axis.In a preferred embodiment, the first connecting member includes a stop member engaged by a first end of the urging member, and the urging member urges the chain guide toward the retracted position.

[0006] The above-mentioned object is further achieved according to a further aspect of the present invention by a bicycle front derailleur, which includes a fixing member defining a fixing member axis and configured to be fixed to a bicycle frame, a chain guide movable between a retracted position and an extended position with respect to the fixing member, a linking mechanism coupling the chain guide to the fixing member, and an urging member urging the chain guide toward the retracted position or the extended position. The linking mechanism includes a first linking member pivotable with respect to the fixing member about a first axis and pivotable with respect to the chain guide about a second axis positioned above the first axis when the fixing member is fixed to the bicycle frame.The link mechanism includes a second link pivotable with respect to the fixing link about a third axis and pivotable with respect to the chain guide about a fourth axis positioned above the third axis when the fixing link is fixed to the bicycle frame, the first link and the second link together forming a four-bar linkage, and the second axis being positioned between the fourth axis and the chain guide. The first link has a first arm and a second arm, each extending between the first and second axes, respectively. The biasing member is disposed between the first arm and the second arm and coaxially about one of the first and second axes. The first arm includes a first upper eyelet and a first lower eyelet.

[0007] Preferably, the first axis and the third axis lie in a first plane, and the second axis and the fourth axis lie in a second plane. The first and second planes are preferably approximately perpendicular to the center axis of the bicycle frame when the fixing member is fixed to the bicycle frame.

[0008] According to a further aspect, the second connecting member has a cable fixing portion, in particular the cable fixing portion is positioned between the second axis and the fourth axis in a substantially horizontal direction.

[0009] According to a further aspect, the loading member is arranged coaxially around the second axis.

[0010] According to a further aspect, the first connecting member includes a stop member which is engaged by means of a first end of the urging member.

[0011] According to a further aspect, the loading link acts on the chain guide in the direction of the retracted position.

[0012] The invention, together with additional features and advantages thereof, may best be understood by reference to the following description. Short description of the drawings Fig. 1 is a perspective view of a bicycle derailleur according to a preferred embodiment of the present invention; Fig. 2 is an exploded perspective view of the bicycle derailleur of the Fig. 1; Fig. 3 is another perspective view of the bicycle derailleur of the Fig. 1; Fig. 4 is a plan view of the bicycle derailleur of the Fig. 1; Fig. 5 is a side elevational view of the bicycle derailleur of Fig. 1; Fig. 6 is another perspective view of the bicycle derailleur of the Fig. 1; and Fig. 7 is a rear elevational view of the bicycle derailleur of Fig. 1.

[0013] Like numbers refer to like parts throughout the different views of the drawings. Detailed description of the preferred embodiments

[0014] Selected embodiments will now be explained with reference to the drawings. From this disclosure, it will be apparent to one skilled in the art that the following descriptions of the embodiments are provided for illustrative purposes only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

[0015] As used herein to describe the present invention, the following directional terms "forward," "backward," "overhead," "below," "vertical," "horizontal," "under," and "across," as well as any other similar directional terms, refer to such directions of a bicycle equipped with the present invention. Accordingly, these terms, as used to describe the present invention, should be interpreted with respect to a bicycle equipped with the present invention used in the normal riding position.

[0016] Referring to the Fig. 1 to 7, a bicycle front derailleur 10 essentially comprises a fixing member 12 configured to be fixed to a bicycle frame, a chain guide 14 guiding a chain (not shown), and a connecting mechanism 16 coupling the chain guide 14 to the fixing member 12. The fixing member 12 is preferably a tubular clamping member or device that can be clamped or otherwise fixed to the bicycle frame, preferably to a seat tube 100 of the bicycle frame (see Fig. 7). However, it should be understood that the bicycle front derailleur 10 can be installed or fixed to other portions of the bicycle, such as the bottom bracket, as needed or desired. In a preferred embodiment, the fixing member 12 is preferably clamped directly to the seat tube 100 of the bicycle frame. As shown in Fig. 2, the fixing member 12 includes a first clamping part 12a, a second clamping part 12b, a pivot pin 12c, and a fastener 22. However, this is not a limitation of the present invention, and any fixing member 12 that fixes the derailleur 10 to a bicycle is within the scope of the present invention. Accordingly, the term "fixing member" as used herein includes a structure suitable for being attached to the seat tube 100 and / or bicycle in a fixed state.

[0017] In a preferred embodiment, the chain guide 40 is movable between a retracted position and an extended position with respect to the fixing member 12. As is known in the art, once the bicycle front derailleur 10 is mounted to the bicycle frame, the action of the chain guide 14 moves the chain to different chainrings of a chainring assembly for the purpose of shifting. The linking mechanism 16 couples the chain guide 14 to the fixing member 12. The linking mechanism 16 includes a first link 18. Preferably, the linking mechanism 16 also includes a second link 20. As shown in the Fig. 5 to 7, in a preferred embodiment, the first link 18 is pivotable with respect to the fixing member 12 about a first axis A1 and pivotable with respect to the chain guide 14 about a second axis A2. As shown in Fig. 5, in a preferred embodiment, the second axis A2 is positioned above the first axis A1 when the fixing member 12 is fixed to the seat tube 100 of the bicycle frame.

[0018] In a preferred embodiment, the connecting mechanism 16 includes a biasing member 24 (e.g., a torsion spring) that biases the chain guide 14 toward the retracted position or the extended position. In a preferred embodiment, the biasing member biases the chain guide 14 toward the fixing member 12. Specifically, the biasing member 24 biases the chain guide 14 toward the retracted position. The biasing member 24 is arranged coaxially about the second axis A2. Preferably, the connecting mechanism 16 includes a pivot pin 26 extending through the center of the biasing member 24.

[0019] As in the Fig. 5 to 7, in a preferred embodiment, the connecting mechanism 16 further includes a second link 20 that is pivotable with respect to the fixing member 12 about a third axis A3 and pivotable with respect to the chain guide 14 about a fourth axis A4. In a preferred embodiment, the fourth axis A4 is positioned above the third axis A3 when the fixing member 12 is fixed to the seat tube 100 of the bicycle frame. It will be understood by one skilled in the art that the first link 18 and the second link 20 together form a four-bar linkage. As shown in Fig. 1, in a preferred embodiment, the second connecting member 20 includes a cable fixing portion 28. As shown in Fig. As shown in Figure 7, in a preferred embodiment, the cable fixing portion 28 is positioned between the second axis A2 and the fourth axis A4 in a substantially horizontal direction. However, this is not a limitation of the present invention.

[0020] When actuated, the second link 20 rotates about the third axis A3, which is substantially perpendicular to and spaced from an axis defined by the fixing member 12 (referred to herein as the fixing member axis A5 and in the Fig. 4 and Fig. 6). It is understood that the third axis A3 extends through the seat tube 100 when the bicycle front derailleur 10 is fixed to the seat tube 100. The first link member 18 rotates about the first axis A1. In a preferred embodiment, the first and third axes A1 and A3 are fixed with respect to the fixing member 12, and the second and fourth axes A2 and A4 are movable with respect to the fixing member 12.

[0021] As explained above, the connecting mechanism 16 is preferably a four-bar linkage mechanism defined by the four rotational axes A1, A2, A3, and A4. A portion of the second link 20 represents a connecting rod D1 between the third and fourth axes A3 and A4. A portion of the first link 18 represents a second connecting rod B2 between the first and second axes A1 and A2. A portion of the chain guide 14 represents the third connecting rod B3 between the second and fourth axes A2 and A4. A portion of the fixing member 12 represents a fourth connecting rod B4 between the first and third axes A1 and A3. In this way, the bicycle front derailleur 10 essentially includes the fixing member 12, the chain guide 14, and the connecting mechanism 16, thereby forming a four-bar linkage mechanism connecting the fixing member 12 and the chain guide 14.

[0022] As in the Fig. 2 and Fig. 5, in a preferred embodiment, the first link member 18 includes a first arm 30 and a second arm 32, each extending between the first and second axes A1 and A2. The biasing member 24 is disposed between the first arm 30 and the second arm 32. Preferably, the first and second arms 30 and 32 are connected by a bridge member 34 spanning therebetween. As shown in Fig. 2, the bridge member 34 separates the first and second arms 30 and 32 into a first upper eyelet 30a and a first lower eyelet 30b, and a second upper eyelet 32a and a second lower eyelet 32b. The first and second upper eyes 30a and 32a each include pivot openings 36a and 36b for receiving the pivot pin 26. The first and second lower eyes 30b and 32b each include pivot openings 36c and 36d for receiving pivot pins 38. The chain guide 14 additionally includes pivot openings 36e and 36f therein, which receive the pivot pin 26 (and at least partially define the second axis A2) and allow the first link 18 to pivot with respect to the chain guide 14. The first clamping part 12a of the fixing member 12 includes first and second fastening flanges 35a and 35b, which each include pivot openings 36g and 36h.The pivot opening 36g receives one of the pivot pins 38 (and at least partially defines the first axis A1), and the pivot opening 36h receives the other of the pivot pins 38 to permit pivoting of the connecting member 18 with respect to the fixing member 12. In a preferred embodiment, the first connecting member 18 includes a stop member 40 that engages a first end 24a of the biasing member 24. As shown in FIG. Fig. 2, in a preferred embodiment, the stop member 40 is positioned on an arm 40a that is integral with and fixed to the first upper eyelet 30a and the bridge member 34. However, the stop member 40 may also extend from the bridge member 34 or from one of the first or second arms 30 or 32.

[0023] The second link 20 is rotatably supported on the fixing link 12 by a pivot pin 42, which extends through a pivot opening 36i in the second link 20 and a pivot opening 36j in the fixing link 12 (and at least partially defines the third axis A3). This arrangement allows the pivoting of the second link 20 with respect to the fixing link 12. A pivot pin 44 extends through a pivot opening 36k in the second link 20 and a pivot opening 36l in the chain guide 14 (and at least partially defines the fourth axis A4). This arrangement allows the pivoting of the second link 20 with respect to the chain guide 14.

[0024] The connecting mechanism 16 is preferably designed such that the biasing member 24, which is coaxial with the second axis A2, always urges the chain guide 14 in a transverse direction toward the frame of the bicycle. In other words, when the chain guide 14 is in a retracted position, the chain engages the chainring of the chainring assembly closest to the seat tube 100. When the connecting mechanism 16 moves the chain guide 14 to its extended position, the chain guide 14 is positioned closest to the outermost chainring of the chainring assembly, specifically the chainring farthest from the seat tube 100. In a further embodiment, the biasing member 24 can be coaxial with the first axis A1.

[0025] In a preferred embodiment, when the derailleur is attached to a bicycle, the first axis A1 and the third axis A3 lie in a first plane, which is approximately perpendicular to a central axis of the bicycle frame or the fixing member axis A5 when the bicycle front derailleur 10 is attached to the seat tube 100 of the bicycle frame. The second axis A2 and the fourth axis A4 lie in the second plane, which is approximately perpendicular to the central axis of the bicycle frame or the fixing member axis A5 when the bicycle front derailleur 10 is attached to the seat tube 100 of the bicycle frame. Furthermore, the second axis A2 and the fourth axis A4 are movable in a direction approximately perpendicular to the fixing member axis A5.

[0026] In understanding the scope of the present invention, the terms "comprising" and its derivatives as used herein are intended to be open-ended terms that specify the presence of the stated features, elements, components, groups, numbers, and / or steps, but do not preclude the presence of other unstated features, elements, components, groups, numbers, and / or steps. The foregoing also applies to terms having a similar meaning, such as the terms "including," "having," and their derivatives.The term "attach" or "attaching", as used herein, includes embodiments in which one element is secured directly to another element by attaching the element directly to the other element; embodiments in which the element is indirectly secured to the other element by attaching the element to intermediate links (links which in turn are attached to other elements; and embodiments in which one element is integrally formed with another element, i.e., one element is essentially a part of the other element). This definition applies to terms with similar meanings, for example, "connected", "coupled", "attached", "glued", "fixed", and their derivatives. Also, the terms "part", "section", "section", "element", or "link", when used individually, can also have an ambiguous meaning of a single element or a plurality of elements.As used herein to describe the above-mentioned embodiments, the following directional terms "forward," "backward," "rightward," "leftward," "outward," "forward," "inward," "downward," "upward," "above," "below," "vertical," "horizontal," and "transverse," as well as any other similar directional terms, refer to such terms of a bicycle equipped with the bicycle front derailleur. Accordingly, these terms, as used to describe the bicycle front derailleur, should be interpreted with respect to a bicycle equipped with the bicycle front derailleur as used in a normal riding position on a level surface. Finally, terms of degree such as "substantially," "approximately," and "approximately," as used herein, mean a reasonable degree of deviation from the modified term such that the end result is not significantly altered.

[0027] Accordingly, although exemplary embodiments of the invention have been shown and described, it is to be understood that all terms as used herein are merely descriptive and not limiting, and that many changes, modifications and substitutions may be made by one skilled in the art without departing from the scope of the invention.

Claims

[1] Bicycle front derailleur (10) comprising: a fixing member (12) configured to be fixed to a bicycle frame; a chain guide (14) movable between a retracted position and an extended position with respect to the fixing member (12); a connecting mechanism (16) that couples the chain guide (14) to the fixing member (12), wherein the connecting mechanism (16) includes a first connecting member (18) that is pivotable with respect to the fixing member (12) about a first axis (A1) and that is pivotable with respect to the chain guide (14) about a second axis (A2) that is positioned above the first axis (A1) when the fixing member (12) is fixed to the bicycle frame, and wherein the connecting mechanism (16) includes a second connecting member (20) that is pivotable with respect to the fixing member (12) about a third axis (A3) and that is pivotable with respect to the chain guide (14) about a fourth axis (A4) that is positioned above the third axis (A3) when the fixing member (12) is fixed to the bicycle frame, wherein the first connecting member (18) and the second connecting member (20) form a four-bar connection,and wherein the second axis (A2) is positioned between the fourth axis (A4) and the chain guide (14); and, an urging member (24) which urges the chain guide (14) in the direction of the retracted position or the extended position, wherein the urging member (24) is arranged coaxially about the second axis (A2), wherein the chain guide (14) includes two pivot openings (36e, 36f) which at least partially define the second axis (A2). [2] A bicycle front derailleur (10) according to claim 1, wherein the first link (18) includes a first arm (30) and a second arm (32), each extending between the first and second axes (A1, A2), and wherein the biasing member (24) is disposed between the first arm (30) and the second arm (32). [3] Bicycle front derailleur (10) comprising: a fixing member (12) configured to be fixed to a bicycle frame, the fixing member (12) defining a fixing member axis (A5); a chain guide (14) movable between a retracted and an extended position with respect to the fixing member (12); a connecting mechanism (16) coupling the chain guide (14) to the fixing member (12), wherein the connecting mechanism (16) includes a first connecting member (18) which is pivotable with respect to the fixing member (12) about a first axis (A1) and which is pivotable with respect to the chain guide (14) about a second axis (A2) positioned above the first axis (A1) when the fixing member (12) is fixed to the bicycle frame, and wherein the connecting mechanism (16) includes a second connecting member (20) which is pivotable with respect to the fixing member (12) about a third axis (A3) and which is pivotable with respect to the chain guide (14) about a fourth axis (A4) when the fixing member (12) is fixed to the bicycle frame, wherein the first connecting member (18) and the second connecting member (20) together form a four-bar connection, and wherein the second axis (A2) is positioned between the fourth axis (A4) and the chain guide (14),wherein the first link (18) has a first arm (30) and a second arm (32), each extending between the first and second axes (A1, A2); and, an actuating member (24) which acts on the chain guide (14) in the direction of the retracted position or the extended position, wherein the biasing member (24) is arranged between the first arm (30) and the second arm (32) and coaxially around the first axis (A1) or the second axis (A2), the first arm (30) including a first upper eyelet (30a) and a first lower eyelet (30b). [4] Bicycle front derailleur (10) according to claim 1 or 3, wherein the first axis (A1) and the third axis (A3) lie in a first plane which is approximately perpendicular to a central axis of the bicycle frame when the fixing member (12) is fixed to the bicycle frame. [5] Bicycle front derailleur (10) according to claim 4, wherein the second axis (A2) and the fourth axis (A4) lie in a second plane, and wherein the second plane is approximately perpendicular to the central axis of the bicycle frame when the fixing member (12) is fixed to the bicycle frame. [6] Bicycle front derailleur (10) according to claim 1 or 3 or 4 or 5, wherein the second link (20) has a cable fixing portion (28), in particular the cable fixing portion (28) is positioned between the second axis (A2) and the fourth axis (A4) in a substantially horizontal direction. [7] Bicycle front derailleur (10) according to one of the preceding claims, wherein the biasing member (24) is arranged coaxially around the second axis (A2). [8] Bicycle front derailleur (10) according to one of the preceding claims, wherein the first connecting member (18) includes a stop member (40) which is engaged by means of a first end (24a) of the urging member (24). [9] Bicycle front derailleur (10) according to one of the preceding claims, in which the biasing member (24) biases the chain guide (14) in the direction of the retracted position.

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